One of the most tedious aspects of online debate is that, as soon as you call someone an idiot, or suggest that their argument is of the kind that would disgrace a below-average chimpanzee, they accuse you of arguing ‘ad-hominem’, which they believe to be a terrible thing.
As the holder of a philosophy degree from a mildly respected institution, I can confirm that this is bollocks.
There is a fallacy in argument called the ‘ad-hominem fallacy‘. It applies to irrelevant personal insults (or compliments) – “yes, Dave Smith is in favour of cutting the speed limit, but he drowns kittens in a sack so we shouldn’t”.
However, this is seldom the way the term is used online: normally, it’s used against two entirely legitimate forms of criticism.
1) If you make a revolting argument and I call it revolting, that’s legitimate comment, not ad-hominem (if you make a revolting argument and I call you fat and ugly, that would have been ad-hominem.)
2) If your background suggests strong and unreasoned partisanship for a particular cause, then it’s more reasonable for me to doubt the factual underpinnings of your case (clearly, not the logic of whether your conclusions flow through your premises) than for an impartial observer.
Since all real-life argument outside of thought experiment relies on accepting some evidence that you’re unable to verify yourself, this means that it’s reasonable to form different opinions on the same argument presented by two different people.
For example, imagine a discussion on lowering the age of consent, as presented by a) a well-respected child psychologist b) a notorious paedophile…
Yeah well, you would say that wouldn't you?
A notorious paedophile? Enough with the straw men!
Or, imagine discussing anything at all with a person who is a) normal and not stupid or b) a self-proclaimed 'libertarian'.
Oh yeah, the use of the term 'strawman' to mean 'analogy I can't refute but that I think is a bit extreme', that's another one.
Once you've been accused on creating a straw man, and if a thread is sufficently long, you can pretty much guarantee someone will wander in and say exactly what your 'straw man' just said.
And you'll probably recognise their name.
Does (b) have a good argument? Did you even listen to it?
When (a) made their case, did you listen to their argument, or to their list of qualifications and 'respect'? Isn't that tantamount to argument from authority?
And who is to say set (a) does not intersect set (b)?
You seem to be implying that (b) makes the argument because they are a paedophile. But maybe they are a known paedophile because they have a good argument for it being morally OK. What if they're right? Would you make the same point should someone argue against lowering the age of consent if you knew that they were personally disgusted by paedophilia? Or if you both knew that people who dare to argue for it generally become pariahs, facing social rejection and even persecution? Can a meat eater argue against compulsory vegetarianism? Or a teacher for the importance of education? From a logical point of view it's the same; they're evidently self-interested in the outcome. But people who have made their minds up already will be careful to make that argument only in the 'right' direction.
And by trading in such strong emotional taboos, there is a risk you may be perceived as comparing those people who disagree with your use of ad hominems to paedophiles. Whether you intended it or not, it gives an unfortunate impression. There's probably some version of Godwin's law for mentioning them, too.